SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7aedaa2e6e397c2c834ff11048941311d26b6c9d8e0b5b392426818686c72db8' 
  AND token = '0svBjlPGfNfUu2zlR1YNhd7+5/FhxDsEDiz4myRHgI4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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