SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '973d100b30eb23913b7a9f57db6bfd5e4c3313a09a64bfc0598580ba7aafd8e2' 
  AND token = 'Oc/1xeJnFV0o5HRfyZ2FUZSD+67m1Q5kRTqV5l0wRCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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