SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5603fce02aabc3e1cd7901918dcc2ba48c4ce2cda3ab64338d45834ad5570790' 
  AND token = 'G/vitIjk8JNuiFFeKYcAfLGqEddKPufCGs95/kDcW6A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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