SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6235ad9219ffaab597352283b00f58506dfa544d8554870d677ae75aeebb8a2' 
  AND token = 'tjq3Knkw/GDUbaYuNgOSqMli/rqkDuGBhLF1Cyx01uQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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