SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '8d7b257235c8fcc2af2873aef88308c52cf0a9b54753744104fbfa3f5ecc2c6b' 
  AND token = 'o8M1ueae5clzOarQuimibPvj0/iD+lDZ49T0mtNkqgU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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