SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ba5a5578bbefc64adcb0cf58055252e2c60ec52521af6a3e41618f098303bb2' 
  AND token = 'oRaJWIoYX0gbAQwDeCDP1Id8hEVBdJYYFmA1n0jgtLk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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