SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23f9e0e300b0d37593bc07997e24d57eb97d61ec05870c48783ca0efbc67f433' 
  AND token = 'U4LhjVjMdrsAOFFxDrOal2g6suCjAT3rPRikysTAT5I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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