SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '883c89acac46db02db575580bc387f0d9dc0d348e66759f16238b2ea5154a77e' 
  AND token = 'YyPv6YIdLph9ndaqlC00i6UTK8VCXjit1qBx+f6TgtE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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