SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '71d332acc91311e4264b792448af2862959cd86aef4b42293762f3288a52c870' 
  AND token = 'BEypHPjDrahzoJuZ68BaitsQP1pOxxkijT7bmQgTAuA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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