SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b42430b93d8f2a068859a0aa4bd107911803146eb273894bfcc4a303535bb4b' 
  AND token = 'pV6SvB0Cl0pQJkP1jdqOtl8hm+f+w7kP/W9FeqWiEqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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