SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1059b818b44984d2b44173484f517798d58deb19f01b3165e236d683c0fad46e' 
  AND token = 'IVDdiPcN6SCoMVQ2QrsevrYnMsV/mEXbU3j8K8mbZRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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