SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '701a511d71440a726623c1d3299d1338ccadfd2ac544a2a1355bf841408a7f09' 
  AND token = '3CUTGW+zGyRvfPjP9XsxogCVec75BLs62z4HW5u8mlY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}