SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32ce0704b7efea7c73ef817a55c9225fa4f8ae3a313f8e8553d5e1006eea6958' 
  AND token = 'xvM6RTMcXqrCk6w61kbq2R1nkUQ4dPMteOMxNygepLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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