SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5402368b0ded5de3923469948cc09481cb3651cf8af42a8003e12e6f7f6404dc' 
  AND token = 'oJFGYCVGF47hU1FDCB+6+rwuV/X34Ln2MuYcm9gMK4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00113

JSON explain

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