SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fefb67c0b24800266fe7bd119bfb4cfba0ffaca6d07c5e34c9a1b55e248f18be' 
  AND token = 'gmpgJckEnCoUhrxIRq9xtfYaGABXtL9AgLIb5HPgnHg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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