SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3dcdb10d3276057c470a1ff3ed826a8f5be21bfabc10bb1eab06a5b56e67f06c' 
  AND token = '4ZKQOWCpEhrxoPsytEqPVrR6DcbyIY05/exjkMvj1rc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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