SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6c313351c23a229ad884740faaa287a1314cb2a405086dd6d199d01bf6178e8b' 
  AND token = '/JKz8R7iq1mz2mHfg+uaahQCNPM1epHsJgkuNAmkYSs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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