SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fda17d26b480b3adc3c501731b20994e324319f074294f0a78f9e6d2487ff30a' 
  AND token = '/dQ6lsnDCYkuXKbNUziS4t5SVWDAKN+PbDglwbGiSn0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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