SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '350c2437b3b0501980d375ec915ceed20f14e77fa6658c3649aff0896eb79f4a' 
  AND token = '5thsikG7MxzoMK0E1CS+Vvg8zOjklUZUQ7lLzH2qq2s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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