SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29b67ef729cbc0c6075a29c5ca4206859f092038e4c58757589ba90af172a763' 
  AND token = 'JKYnEYDAX0kyD2uqqDGKhlYfPhrfCG2syujt2nby32o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}