SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'eb77f26bab31213053f086bdbcf0a689c32f71bf73f88ff2deec0d85ae344650' 
  AND token = 'XF7hJv8ti2D/VE/jtvRG4B7oRfaZBrRWqLdIW7uNY4s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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