SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cc6404d57547ddad18747fe2caac4cae7df63ee553aabf38db55806669bae52' 
  AND token = '+sX4S1CFYooTCWcNtCsHlLbLdtzVYDtRt08KEueHjOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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